The present invention relates to coffee mug lids in general. More specifically to a lid that has a spring loaded, gasketed valve that opens when a finger twist knob is rotated permitting coffee to be released from the mug and sealed when rotated in reverse.
Previously, many types of lids have been used in endeavoring to provide an effective means to enclose a coffee mug or cup. In the past coffee mugs and cups are normally sealed by the use of a resilient cover that snaps over a rim on the top and must be manually removed and replaced. Some mugs have lids that include some type of valve or release mechanism permitting the user to seal the mug when not in use.
A the prior art listed below did not disclose any patents that possess any of the novelty of the instant invention, however the following U.S. patents are considered related:
Letsch et al. in U.S. Pat. No. 4,754,888 discloses a carafe with an inner container surrounded by a casing. The inner container and the casing have an opening at the top which may be closed by a separate plug. The plug and opening in the container and casing are shaped such that it is possible to fill or empty the inner container while the plug is still in the opening. The plug and container both have mating grooves that provide opposed flow paths into and out of the container. The container also includes a basin around the top for receiving coffee from a coffee maker and the plug has openings to provide a flow path from the basin into the container interior.
Karp in U.S. Pat. No. 5,249,703 teaches a travel mug that includes a container and a lid in combination. The container has a handle and an annular lip that has an annulus capable of forming a seal with the top side of the annular lip. A cylindrical well in the lid has a vertical dividing wall such that the lid may be readily rotated by hand. The retaining arms extend from the underside of the lid and engage the underside of the annular lip to pull it into tight abutment. Diametrically opposed gaps in the lip act as passageway for the retaining arms. Similarly diametrically opposed notches in the lid align with the gaps to allow liquid to be poured from the container.
U.S. Pat. No. 5,918,761 issued to Wissinger is for an insulated container and cover combination that has an outer container shell terminating at an opening with a surrounding edge. An inner container shell is nested within the outer container shell and has an opening surrounded by a continuous edges in abutment with the surrounding edge. The inner container shell is spaced inwardly and is out of contact with the outer shell. A cover mounting assembly is attached to the outer shell adjacent to the opening. A single seal, made of elastomeric material, has a sealing surface disposed at the interface of the shells. Locating rings define the removable cover mounting assembly and locate the single sealing ring on the inner and outer shells.
For background purposes and as indicative of the art to which the invention is related reference may be made to the remaining cited design patents.
Many types of mug lids are in common use today particularly with the wide acceptance of stainless steel and dual wall plastic mugs in a myriad of configurations. Liquids such as coffee, tea and hot chocolate etc. are often carried in mugs throughout the day and even when traveling in vehicles. Song with the difficulty of keeping the liquid hot, spillage is probably the larger obstacle to overcome.
It is therefore a primary object of the invention to provide the public with a lid that is continually, sealed until manually opened by a deliberate act of twisting a finger knob. This invention provides a liquid tight seal, under spring pressure, with a gasket continually forced onto a valve seat such that if the mug is inadvertently tipped over no liquid will be released from the mug. There are many other types of lids available in today""s market that have openings with covers but if tipped over, particularly if they remain horizontal, have a tendency to leak and spill coffee or other staining liquids onto the surface. Most lids in this category have sliding valves that are operated by hand or small caps that hinge out of the way however true liquid tight seals are uncommon or require extensive manual manipulation to accomplish such a union.
An important object of the invention is that it is easy to understand its operation as one simply rotates the finger twist knob in a clock wise direction and the lid opens and stays open until it is twisted in the reverse direction when the lid automatically reverts to its normally closed and sealed position with the spring tension assuring a tight seal. Indicia located on the top of the dome indicate the position of the valve in a universal manner with symbols or written words in the language used.
Another object of the invention is that the mug may be used in any orientation, that is to say, once the valve is opened the mug may be turned in any direction relative to the handle and the coffee or liquid is always available around the lip. This object is realized by the use of a series of outlet ports completely around the raised lip of the lid. The liquid always remains level therefore if the mug is tipped in the drinking attitude the liquid will flow from the appropriate set of ports regardless of where the handle is positioned.
Yet another object of the invention is its ability to be cleaned easily. Cleaning is particularly simple as the lid may be emerged in water and cleaning inside is a simple matter of allowing the water to dissolve the residue inside. The valve may be open or closed during this cleaning procedure however it is more thorough if the lid is in the open position as the interface of the gasket to the lid body seat would be cleaned. The compression spring is fabricated of stainless steel and the balance of the lid is thermoplastic which will not rust or deteriorate.
Still another object of the invention is that it has few moving parts which interface with each other and the material has ample structural integrity to eliminate breakage and undue wear.
A final object of the invention is that it easy to manufacture since few parts are used and it is not difficult to assemble making it cost effective to produce.